A Significant Improvement in the Electrocatalytic Stability of N‑Doped Graphene Nanosheets Used as a Counter Electrode for [Co(bpy)₃]^3+/2+ Based Porphyrin-Sensitized Solar Cells

A significant improvement in efficiency is achieved for porphyrin (YD2-o-C8) based dye-sensitized solar cells, coupled with [Co­(bpy)₃]^3+/2+ mediator electrolyte. However, the poison of the counter electrode (CE) by the [Co­(bpy)₃]^3+/2+ mediator remains a significant barrier to producing a reliable high-performance device. In this paper, nitrogen-doped graphene nanosheets (NG) are produced using a low-cost solution-based process and are used as the CE for [Co­(bpy)₃]^3+/2+ based porphyrin-sensitized solar cells. These produce significantly better electrocatalytic activity than the commonly used Pt CE. The superior performance is a result of the increased number of catalytic sites and the wettable surface that is caused by the substitution of pyridinic and pyrrolic N into the carbon-conjugated lattice. To the authors’ best knowledge, the significantly improved cycling stability (>1000 times) of NG CE for [Co­(bpy)₃]^3+/2+ redox complexes is demonstrated for the first time

A Significant Improvement in the Electrocatalytic Stability of N‑Doped Graphene Nanosheets Used as a Counter Electrode for [Co(bpy)₃]^3+/2+ Based Porphyrin-Sensitized Solar Cells

A significant improvement in efficiency is achieved for porphyrin (YD2-o-C8) based dye-sensitized solar cells, coupled with [Co­(bpy)₃]^3+/2+ mediator electrolyte. However, the poison of the counter electrode (CE) by the [Co­(bpy)₃]^3+/2+ mediator remains a significant barrier to producing a reliable high-performance device. In this paper, nitrogen-doped graphene nanosheets (NG) are produced using a low-cost solution-based process and are used as the CE for [Co­(bpy)₃]^3+/2+ based porphyrin-sensitized solar cells. These produce significantly better electrocatalytic activity than the commonly used Pt CE. The superior performance is a result of the increased number of catalytic sites and the wettable surface that is caused by the substitution of pyridinic and pyrrolic N into the carbon-conjugated lattice. To the authors’ best knowledge, the significantly improved cycling stability (>1000 times) of NG CE for [Co­(bpy)₃]^3+/2+ redox complexes is demonstrated for the first time

Analysis of Pirlimycin Residues in Beef Muscle, Milk, and Honey by a Biotin–Streptavidin-Amplified Enzyme-Linked Immunosorbent Assay

Food contamination by veterinary drug residues is a worldwide public health concern and requires continuous monitoring. In this study, we developed a biotin–streptavidin-amplified ELISA (BA-ELISA) using a produced monoclonal antibody for detecting pirlimycin residues in beef muscle, milk, and honey. The IC₅₀ value of the BA-ELISA was 1.6 ng/mL for pirlimycin in buffer, and the sensitivity was improved 3 times compared to traditional ELISAs. The optimized BA-ELISA can be used to quantitate trace amounts of pirlimycin residues in beef muscle, milk, and honey. This method had limits of detection (LODs) of 4.45 μg/kg in beef muscle, 1.65 μg/L in milk, and 2.75 μg/kg in honey. The average recovery of the BA-ELISA ranged from 78 to 97%, and the coefficient of variation ranged from 5.3 to 13.5%. The developed BA-ELISA method was validated using LC-MS/MS, and the BA-ELISA can be used for routine screening analysis of pirlimycin residues

Construction of Synergistic Fe₅C₂/Co Heterostructured Nanoparticles as an Enhanced Low Temperature Fischer–Tropsch Synthesis Catalyst

Iron and cobalt catalysts are two major categories for commercial Fischer–Tropsch synthesis (FTS) catalysts. The two types of catalysts have distinct merits and shortcomings while they are largely supplementary to each other. However, until now, there has been a lack of an efficient way to properly combine those two catalysts into a synergistic one which possesses the benefits of both catalysts. Herein, the Fe₅C₂/Co heterostructured nanoparticles (NPs) were constructed by a secondary growth strategy, where the Fe/Co molar ratio can be tuned from 3.3 to 25. Based on the FTS reaction evaluation, we observed that only with 0.6 wt % Co (Fe/Co = 12) incorporated, the Fe₅C₂/Co catalyst exhibits an activity four times higher than that of pure Fe₅C₂ catalyst at low temperature. In this catalyst, Co was responsible for the CO dissociation while Fe₅C₂ was responsible for the chain growth at 220 °C. The synergistic effect of both sites may lead to enhanced performance in FTS reaction. This result provides a perspective for the construction of Fe–Co bimetallic FTS catalysts

Data File 3: Order-of-magnitude multiphoton signal enhancement based on characterization of absorption spectra of immersion oils at the 1700-nm window

supplementary material 3 Originally published in Optics Express on 20 March 2017 (oe-25-6-5909

Image_1_CD8+ T and NK cells characterized by upregulation of NPEPPS and ABHD17A are associated with the co-occurrence of type 2 diabetes and coronary artery disease.jpeg

BackgroundCoronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) are closely related. The function of immunocytes in the pathogenesis of CAD and T2DM has not been extensively studied. The quantitative bioinformatics analysis of the public RNA sequencing database was applied to study the key genes that mediate both CAD and T2DM. The biological characteristics of associated key genes and mechanism of CD8+ T and NK cells in CAD and T2DM are our research focus.MethodsWith expression profiles of GSE66360 and GSE78721 from the Gene Expression Omnibus (GEO) database, we identified core modules associated with gene co-expression relationships and up-regulated genes in CAD and T2DM using Weighted Gene Co-expression Network Analysis (WGCNA) and the ‘limma’ software package. The enriched pathways of the candidate hub genes were then explored using GO, KEGG and GSEA in conjunction with the immune gene set (from the MSigDB database). A diagnostic model was constructed using logistic regression analysis composed of candidate hub genes in CAD and T2DM. Univariate Cox regression analysis revealed hazard ratios (HRs), 95% confidence intervals (CIs), and p-values for candidate hub genes in diagnostic model, while CIBERSORT and immune infiltration were used to assess the immune microenvironment. Finally, monocytes from peripheral blood samples and their immune cell ratios were analyzed by flow cytometry to validate our findings.ResultsSixteen candidate hub genes were identified as being correlated with immune infiltration. Univariate Cox regression analysis revealed that NPEPPS and ABHD17A were highly correlated with the diagnosis of CAD and T2DM. The results indicate that CD8+ T cells (p = 0.04) and NKbright cells (p = 3.7e-3) are significantly higher in healthy controls than in individuals with CAD or CAD combined with T2DM. The bioinformatics results on immune infiltration were well validated by flow cytometry.ConclusionsA series of bioinformatics studies have shown ABHD17A and NPEPPS as key genes for the co-occurrence of CAD and T2DM. Our study highlights the important effect of CD8+ T and NK cells in the pathogenesis of both diseases, indicating that they may serve as viable targets for diagnosis and therapeutic intervention.</p

Image_3_CD8+ T and NK cells characterized by upregulation of NPEPPS and ABHD17A are associated with the co-occurrence of type 2 diabetes and coronary artery disease.jpeg

BackgroundCoronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) are closely related. The function of immunocytes in the pathogenesis of CAD and T2DM has not been extensively studied. The quantitative bioinformatics analysis of the public RNA sequencing database was applied to study the key genes that mediate both CAD and T2DM. The biological characteristics of associated key genes and mechanism of CD8+ T and NK cells in CAD and T2DM are our research focus.MethodsWith expression profiles of GSE66360 and GSE78721 from the Gene Expression Omnibus (GEO) database, we identified core modules associated with gene co-expression relationships and up-regulated genes in CAD and T2DM using Weighted Gene Co-expression Network Analysis (WGCNA) and the ‘limma’ software package. The enriched pathways of the candidate hub genes were then explored using GO, KEGG and GSEA in conjunction with the immune gene set (from the MSigDB database). A diagnostic model was constructed using logistic regression analysis composed of candidate hub genes in CAD and T2DM. Univariate Cox regression analysis revealed hazard ratios (HRs), 95% confidence intervals (CIs), and p-values for candidate hub genes in diagnostic model, while CIBERSORT and immune infiltration were used to assess the immune microenvironment. Finally, monocytes from peripheral blood samples and their immune cell ratios were analyzed by flow cytometry to validate our findings.ResultsSixteen candidate hub genes were identified as being correlated with immune infiltration. Univariate Cox regression analysis revealed that NPEPPS and ABHD17A were highly correlated with the diagnosis of CAD and T2DM. The results indicate that CD8+ T cells (p = 0.04) and NKbright cells (p = 3.7e-3) are significantly higher in healthy controls than in individuals with CAD or CAD combined with T2DM. The bioinformatics results on immune infiltration were well validated by flow cytometry.ConclusionsA series of bioinformatics studies have shown ABHD17A and NPEPPS as key genes for the co-occurrence of CAD and T2DM. Our study highlights the important effect of CD8+ T and NK cells in the pathogenesis of both diseases, indicating that they may serve as viable targets for diagnosis and therapeutic intervention.</p

Image_2_CD8+ T and NK cells characterized by upregulation of NPEPPS and ABHD17A are associated with the co-occurrence of type 2 diabetes and coronary artery disease.jpeg

BackgroundCoronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) are closely related. The function of immunocytes in the pathogenesis of CAD and T2DM has not been extensively studied. The quantitative bioinformatics analysis of the public RNA sequencing database was applied to study the key genes that mediate both CAD and T2DM. The biological characteristics of associated key genes and mechanism of CD8+ T and NK cells in CAD and T2DM are our research focus.MethodsWith expression profiles of GSE66360 and GSE78721 from the Gene Expression Omnibus (GEO) database, we identified core modules associated with gene co-expression relationships and up-regulated genes in CAD and T2DM using Weighted Gene Co-expression Network Analysis (WGCNA) and the ‘limma’ software package. The enriched pathways of the candidate hub genes were then explored using GO, KEGG and GSEA in conjunction with the immune gene set (from the MSigDB database). A diagnostic model was constructed using logistic regression analysis composed of candidate hub genes in CAD and T2DM. Univariate Cox regression analysis revealed hazard ratios (HRs), 95% confidence intervals (CIs), and p-values for candidate hub genes in diagnostic model, while CIBERSORT and immune infiltration were used to assess the immune microenvironment. Finally, monocytes from peripheral blood samples and their immune cell ratios were analyzed by flow cytometry to validate our findings.ResultsSixteen candidate hub genes were identified as being correlated with immune infiltration. Univariate Cox regression analysis revealed that NPEPPS and ABHD17A were highly correlated with the diagnosis of CAD and T2DM. The results indicate that CD8+ T cells (p = 0.04) and NKbright cells (p = 3.7e-3) are significantly higher in healthy controls than in individuals with CAD or CAD combined with T2DM. The bioinformatics results on immune infiltration were well validated by flow cytometry.ConclusionsA series of bioinformatics studies have shown ABHD17A and NPEPPS as key genes for the co-occurrence of CAD and T2DM. Our study highlights the important effect of CD8+ T and NK cells in the pathogenesis of both diseases, indicating that they may serve as viable targets for diagnosis and therapeutic intervention.</p

Insights into Interfacial Synergistic Catalysis over Ni@TiO_2–<i>x</i> Catalyst toward Water–Gas Shift Reaction

The mechanism on interfacial synergistic catalysis for supported metal catalysts has long been explored and investigated in several important heterogeneous catalytic processes (e.g., water–gas shift (WGS) reaction). The modulation of metal–support interactions imposes a substantial influence on activity and selectivity of catalytic reaction, as a result of the geometric/electronic structure of interfacial sites. Although great efforts have validated the key role of interfacial sites in WGS over metal catalysts supported on reducible oxides, direct evidence at the atomic level is lacking and the mechanism of interfacial synergistic catalysis is still ambiguous. Herein, Ni nanoparticles supported on TiO_2–<i>x</i> (denoted as Ni@TiO_2–<i>x</i>) were fabricated via a structure topotactic transformation of NiTi-layered double hydroxide (NiTi-LDHs) precursor, which showed excellent catalytic performance for WGS reaction. <i>In situ</i> microscopy was carried out to reveal the partially encapsulated structure of Ni@TiO_2–<i>x</i> catalyst. A combination study including <i>in situ</i> and <i>operando</i> EXAFS, <i>in situ</i> DRIFTS spectra combined with TPSR measurements substantiates a new redox mechanism based on interfacial synergistic catalysis. Notably, interfacial Ni species (electron-enriched Ni^δ− site) participates in the dissociation of H₂O molecule to generate H₂, accompanied by the oxidation of Ni^δ−–O_<i>v</i>–Ti³⁺ (O_<i>v</i>: oxygen vacancy) to Ni^δ+–O–Ti⁴⁺ structure. Density functional theory calculations further verify that the interfacial sites of Ni@TiO_2–<i>x</i> catalyst serve as the optimal active site with the lowest activation energy barrier (∼0.35 eV) for water dissociation. This work provides a fundamental understanding on interfacial synergistic catalysis toward WGS reaction, which is constructive for the rational design and fabrication of high activity heterogeneous catalysts